There is a slight difference in golf swing techniques between instructors. It is said that there are 100 or more (or 500 or more) swing check points. However, when these check points are arranged and classified, they are reduced to several basic check points. Examples of such basic check points are to correctly grip the club and take a correct stance, not to make a head-up, not to move the head, not to open the armpits, not to impact the ball by using the hands or arms from the top, i.e., make a swing by twisting the body about the backbone by using muscles of the body, that is, taking a right hand golfer as an example, shift the weight from the right foot to the left foot, etc.
While there are a large number of golf swing check points as noted above, it is impossible to make a swing while checking all these points in a short swing time of a couple of seconds. However, by mastering check points which are thought to be most important, ideal movements are acquired to obtain naturally good movements which satisfy most of the other check points as well.
These check points have to be mastered as a basic technique. However, it is impossible to visually confirm the swing form. Therefore, the swing form is liable to be deviated to result in score-down. Further, even when the training person has become able to swing the golf club after mastering the above check points, he or she may not be able to provide a sufficient distance in a long hole or may produce a misshot so that he or she can not improve the score. Particularly, woman golfers and like persons who are not so tall or persons who do not have much muscles can not produce long distance. Inevitably, they try to increase the distance and therefore forget making the proper golf swing. For instance, they often swing the golf club with the arms or hands from the top, thus resulting in misshots or swing form deviation and making the golf play more difficult.
In order that even a person who is not so tall and does not have much physical power be able to hit the ball for a long distance by increasing the head speed, make a high level golf swing to cause the ball to fly along a steady orbit and maintain handicap between zero and single figure, the inventor endeavored to improve the golfer's own swing form, studied by comparing the swing forms of famous home and foreign professional golfers and by comparing methods of improving golf play recommended by professional golfers.
As a result, the inventor found that the methods of improving golf play recommended by the professional golfers involve what are thought to be secret as know-how. But as a result of detailed analysis of video tapes and continuous pictures showing swing forms of professional golfers, it has been found that there is a substantially common swing. The content of the swing is that at the turn-over from the top the upper and lower bodies are moving in opposite directions concurrently although for a very short period of time. This golf swing was exercised repeatedly, and extremely good results could be obtained with stability of the swing form.
The golf swing that has been found will now be described in greater detail. A right hand golfer will be taken as an example. First, when the golfer gets into the back swing from the address, the body is twisted clockwise about the backbone. When the golfer's left shoulder is brought into contact with the left side of the chin, that is, at a 80 to 90% back swing position or slightly before the top, the golfer intuitively begins to cause simultaneous sliding of the left knee and the left waist by several centimeters in the flying direction for down-swinging. As a result, a time difference is produced, and the lower body turns to be rotated counterclockwise while effecting a sliding for several centimeters toward the target, while the upper body continues to be rotated clockwise due to the momentum toward the top position. Thus, for a very short moment the upper and lower bodies are moved in the opposite directions so that the body is twisted greatly. When the upper body being rotated clockwise is pulled with the lead of the lower body and stopped, it turns to be rotated counterclockwise with the body muscles as a spring and under the principles of twisting and lever, thus getting into the down swing. The down swing is brought about from the body turn swing with the body muscles with the lead of the lower body. A high head speed thus can be obtained for ball impact. When the golfer subsequently gets into the follow-through, if the state of contact between the right shoulder and the right side of the chin with each other can be confirmed, it means that a good swing without head-up could be obtained.
As shown above, the ideal and desirable golf swing is a commonly termed down swing with the lead of the lower body, in which the golfer, having gotten into the back swing from the address and reaching the top, turns to go to the down swing by twisting the lower body, i.e., waist and legs, in the direction of the down swing. If the golfer can make such a down swing with the lead of the lower body, a good swing, and hence a good shot, can be obtained. However, most of the golfer's misshots stem from the commonly termed hand swing, i.e., down swing with the lead of the upper body, in the turn-over from the top.
The down swing with the lead of the lower body can be realized by the intuitive play of the golfer himself or herself. In many actual cases, however, the golfer can not recognize by himself or herself whether he or she is in the state of the down swing with the lead of the lower body or the state of the hand swing. Therefore, it is inevitable to let an adviser watch the swing form and receive advices. However, it is impossible to receive advices from an adviser at all times.
Accordingly, researches and investigations were conducted about the method of making the hand swing difficult and permitting stable down swing with the lead of the lower body. As a result, it was found that as the back swing is gradually accelerated toward the top to produce a maximum speed near the top, that is, by increasing the momentum toward the top, the shaft flexes to make it difficult to use the hands or arms, thus permitting the ideal swing with the lead of the lower body while it is tried to make a hand swing. The inventor conducted extensive researches and investigations with an aim of permitting one to master such a golf swing and, as a result, could provide a golf swing training device according to the invention. Professional golfers say that 80% of whether a shot is good or not is determined by the back swing. However, there is no one who says such know-how or secret as what back swing is effective for obtaining the golf club shaft flexing at the top. Further, there is no one who says that such a swing permits maximum merits to be obtained.
Accordingly, the invention conducted extensive researches and investigations with an aim of permitting one to master such an ideal swing and, as a result, could provide a golf swing training device according to the invention. Prior to the filing of the present application, the inventor made a survey of prior arts using a computer but could not find out any invention which seemed to appertain the present invention.